Thioethers, methods for their preparation, and compositions including such thioethers

ABSTRACT

Disclosed are thioethers, methods for preparing such thioethers, and curable compositions, such as coating and sealant compositions, that include such thioethers. The thioethers can be the reaction product of (a) an alpha, omega dihalo organic compound, (b) a metal hydrosulfide, and (c) a metal hydroxide.

FIELD OF THE INVENTION

The present invention is directed to thioethers, methods for preparingsuch thioethers, and curable compositions, such as coating and sealantcompositions, that include such thioethers.

BACKGROUND OF THE INVENTION

Thiol-terminated sulfur-containing compounds are known to be well-suitedfor use in various applications, such as aerospace sealant compositions,due, in large part, to their fuel-resistant nature upon cross-linking.Other desirable properties for aerospace sealant compositions includelow temperature flexibility, short curing time (the time required toreach a predetermined strength) and elevated-temperature resistance,among others. Sealant compositions exhibiting at least some of thesecharacteristics and containing thiol-terminated sulfur-containingcompounds are described in, for example, U.S. Pat. Nos. 2,466,963,4,366,307, 4,609,762, 5,225,472, 5,912,319, 5,959,071, 6,172,179,6,232,401, 6,372,849 and 6,509,418.

Polythioethers that are liquid at room temperature and pressure and haveexcellent low temperature flexibility and fuel resistance, such as aredisclosed in U.S. Pat. No. 6,172,179, are often desired is aerospacesealant applications, for example. Unfortunately, such polythioetherscan be relatively expensive to manufacture due to raw material costs,particularly certain polythiols from which such polythioethers arederived. As a result, it would be desirable to provide novel thioethersthat exhibit acceptable, sometimes surprisingly excellent, properties,such as fuel-resistance and elevated-temperature resistance, as comparedto those described in the prior art but that are capable of beingproduced without the use of a polythiol and, therefore, are capable ofbeing produced at reduced cost as compared to polythioethers derivedfrom certain polythiols.

The present invention has been developed in view of the foregoing.

SUMMARY OF THE INVENTION

In certain respects, the present invention is directed to thioethers.These thioethers of the present invention comprise the structure (I):

—[—S—(RX)_(p)—(R₁X)_(q)—R₂—]_(n)—  (I)

in which:

(a) each R, which may be the same or different, denotes a C₂₋₁₀n-alkylene group, such as a C₂₋₆ n-alkylene group; a C₂₋₁₀ branchedalkylene group, such as a C₂₋₆ branched or a C₃₋₆ branched alkylenegroup having one or more pendant groups which can be, for example, alkylgroups, such as methyl or ethyl groups; a C₆₋₈ cycloalkylene group; aC₆₋₁₄ alkylcycloalkylene, such as a C₆₋₁₀ alkylcycloalkylene group; or aC₈₋₁₀ alkylarylene group;

(b) each R₁, which may be the same or different, denotes a C₁₋₁₀n-alkylene group, such as a C₁₋₆ n-alkylene group; a C₂₋₁₀ branchedalkylene group, such as a C₂₋₆ or C₃₋₆ branched alkylene group havingone or more pendant groups which can be, for example, alkyl groups, suchas methyl or ethyl groups; a C₆₋₈ cycloalkylene group; a C₆₋₁₄alkylcycloalkylene, such as a C₆₋₁₀ alkylcycloalkylene group; or a C₈₋₁₀alkylarylene group;

(c) each R₂, which may be the same or different, denotes a C₂₋₁₀n-alkylene group, such as a C₂₋₆ n-alkylene group; a C₂₋₁₀ branchedalkylene group, such as a C₂₋₆ branched or a C₃₋₆ branched alkylenegroup having one or more pendant groups which can be, for example, alkylgroups, such as methyl or ethyl groups; a C₆₋₈ cycloalkylene group; aC₆₋₁₄ alkylcycloalkylene, such as a C₆₋₁₀ alkylcycloalkylene group; or aC₈₋₁₀ alkylarylene group;

(d) each X, which may be the same or different, denotes O, S, or N—R₁,wherein R₁ is as described above;

(e) p has a value of 1 to 5;

(f) q has a value of 0 to 5;

(g) n has a value of at least 1, such as at least 2, and in some cases 2to 60, 3 to 60, or 25 to 35; and

(h) at least one, in some cases each, R and R₁ are different from eachother.

In other respects, the present invention is directed to invention isdirected to thioethers that comprise the structure (I), wherein:

(a) R denotes a C₂ n-alkylene group;

(b) R₁ denotes a C₁ n-alkylene group;

(c) R₂ denotes a C₂ n-alkylene group;

(d) X denotes O;

(e) p has a value of 1;

(f) q has a value of 1; and

(g) n has a value of at least 1, such as at least 2, and in some cases 2to 60, 3 to 60, or 25 to 35.

In yet other respects, the present invention is directed to thioethersthat are the reaction product of reactants comprising: (a) an alpha,omega dihalo organic compound, (b) a metal hydrosulfide, and (c) a metalhydroxide.

In still other respects, the present invention is directed to curablecompositions, such as coating and sealant compositions, that comprisesuch thioethers.

The present invention is also directed to, inter alia, methods formaking such thioethers.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

For purposes of the following detailed description, it is to beunderstood that the invention may assume various alternative variationsand step sequences, except where expressly specified to the contrary.Moreover, other than in any operating examples, or where otherwiseindicated, all numbers expressing, for example, quantities ofingredients used in the specification and claims are to be understood asbeing modified in all instances by the term “about”. Accordingly, unlessindicated to the contrary, the numerical parameters set forth in thefollowing specification and attached claims are approximations that mayvary depending upon the desired properties to be obtained by the presentinvention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard variation found in theirrespective testing measurements.

Also, it should be understood that any numerical range recited herein isintended to include all sub-ranges subsumed therein. For example, arange of “1 to 10” is intended to include all sub-ranges between (andincluding) the recited minimum value of 1 and the recited maximum valueof 10, that is, having a minimum value equal to or greater than 1 and amaximum value of equal to or less than 10.

As indicated, certain embodiments of the present invention are directedto thioethers. As used herein, the term “thioether” refers to compoundscomprising at least one, often at least two thioether linkages; that is“—CH₂—S—CH₂—” linkages. In certain embodiments, such compounds are apolymer. As used herein, “polymer” refers to oligomers and bothhomopolymers and copolymers. Unless stated otherwise, if used herein,molecular weights are number average molecular weights for polymericmaterials indicated as “Mn” and obtained by gel permeationchromatography using a polystyrene standard in an art-recognized manner.

Certain embodiments of the present invention are directed to thioethersthat comprise a structure having the formula (I), described earlier.More particularly, with respect to formula (I), in certain embodiments:(a) each R, which may be the same or different, denotes a C₂₋₁₀n-alkylene group, such as a C₂₋₆ n-alkylene group; (b) each R₁, whichmay be the same or different, denotes a C₁₋₁₀ n-alkylene group, such asa C₁₋₆ n-alkylene group; (c) each R₂, which may be the same or differentdenotes a C₂₋₁₀ n-alkylene group, such as a C₂₋₆ n-alkylene group; (d)each X denotes O; (e) p has a value of from 1 to 5; (f) q has a value of0 to 5; (g) n has a value of at least 1, often at least two, such as 2to 60, 3 to 60, or, in some cases 25 to 35; and (h) R and R₁ aredifferent from each other. Furthermore, in certain embodiments, withrespect to formula (I): (a) R denotes a C₂ n-alkylene group; (b) R₁denotes a C₁ n-alkylene group; (c) R₂ denotes a C₂ n-alkylene group; (d)X denotes 0; (e) p has a value of 1; (f) q has a value of 1; and (g) nhas a value of at least 1, often at least two, such as 2 to 60, 3 to 60,or, in some cases 25 to 35.

In certain embodiments, the thioethers of the present invention have astructure according to formula (II):

A-(—R³)₂  (II)

wherein: (a) A denotes a structure having the formula (I); and (b) eachR³, which may be the same or different, comprises —SH; —OH, alkyl, suchas a C₁₋₁₀ n-alkyl group, alkylene, such as a C₁₋₁₀ n-alkylene group,—NCO,

or a hydrolyzable functional group, such as a silane group, i.e.,

wherein R and R₁ each independently represent an organic group and x is1, 2, or 3.

Thioethers in which R³ is —SH are “uncapped,” that is, include unreactedterminal thiol groups. Thioethers according to the invention alsoinclude “capped” thioethers, that is, thioethers including terminalgroups other than unreacted thiol groups. These terminal groups can be,for example, any of the groups mentioned above, such as:

(i) —OH, such as could be obtained by, for example, (a) reacting anuncapped thioether of the present invention with a monoxide, such asethylene oxide, propylene oxide, and the like, in the presence of abase, or (b) reacting an uncapped thioether of the present inventionwith an olefinic alcohol, such as, for example, allyl alcohol, or amonovinylether of a diol, such as, for example, ethylene glycolmonovinyl ether, propylene glycol monovinyl ether, and the like, in thepresence of a free radical initiator; (ii) alkyl, such as could beobtained by reacting an uncapped thioether of the present invention withan alkylene; (iii) alkylene, such as could be obtained by reacting anuncapped thioether of the present invention with an diolefin; (iv) —NCO,such as could be obtained by reacting an uncapped thioether of thepresent invention with a polyisocyanate;

such as could be obtained by reacting an uncapped thioether of thepresent invention with a glycidylolefin; or (vi) a hydrolyzablefunctional group, such as could be obtained by reacting an uncappedthioether of the present invention with an olefinic alkoxysilane.

In certain embodiments, therefore, the thioether of the presentinvention is an uncapped thioether comprising the structure (III):

HS—[—S—(RX)_(p)—(R₁X)_(q)—R₂—]_(n)—SH  (III)

Certain embodiments of the present invention are directed to thioethersthat comprise a structure having the formula (III), wherein: (a) each R,which may be the same or different, denotes a C₂₋₁₀ n-alkylene group,such as a C₂₋₆ n-alkylene group; (b) each R₁, which may be the same ordifferent, denotes a C₁₋₁₀ n-alkylene group, such as a C₁₋₆ n-alkylenegroup; (c) each R₂, which may be the same or different denotes a C₂₋₁₀n-alkylene group, such as a C₂₋₆ n-alkylene group; (d) each X denotes O;(e) p has a value of from 1 to 5; (f) q has a value of 0 to 5; (g) n hasa value of at least 1, in some cases at least 2, such as 2 to 60, 3 to60, or 25 to 35; and (h) R and R₁ are different from each other.Furthermore, in certain embodiments, with respect to formula (III): (a)R denotes a C₂ n-alkylene group; (b) R₁ denotes a C₁ n-alkylene group;(c) R₂ denotes a C₂ n-alkylene group; (d) X denotes O; (e) p has a valueof 1; (f) q has a value of 1; and (g) n has a value of at least 1, insome cases at least 2, such as 2 to 60, 3 to 60, or 25 to 35.

In certain embodiments, the thioether of the present invention has theformula (IV):

B-(A-R₃)_(z)  (IV)

in which: (a) B denotes a z-valent residue of a polyfunctionalizingagent; (b) A denotes a structure having the formula (I); (c) each R₃,which may be the same or different, comprises —SH; —OH, alkyl, such as aC₁₋₁₀ n-alkyl group, alkylene, such as a C₁₋₁₀ n-alkylene group, —NCO,

or a hydrolyzable functional group, such as a silane group, i.e.,

wherein R and R₁ each independently represent an organic group and x is1, 2, or 3; and (d)z is an integer from 3 to 6.

That is, the polyfunctionalized embodiments include three or morestructures of the formula (I) bound to the residue of an appropriatepolyfunctionalizing agent. In certain embodiments, z is 3, and thepolyfunctionalizing agent thus is a trifunctionalizing agent. In otherembodiments, the average functionality of the thioether ranges betweenabout 2.05 and about 3.00.

In certain embodiments, the thioethers of the present invention areformed from reactants comprising, or, in some cases, consistingessentially of, or, in yet other cases, consisting of, (i) an alpha,omega dihalo organic compound, such as “x” moles thereof, (ii) a metalhydrosulfide, such as ≧2x moles thereof, (iii) a metal hydroxide, suchas ≧2x moles thereof and optionally, (iv) a desired amount ofpolyfunctionalizing agent. In certain embodiments, the thioethers of thepresent invention are formed from reactants that are substantially free,or, in some cases, completely free, of any polythiol. As used herein,the term “substantially free” means that the material being discussed ispresent, if at all, as an incidental impurity. In other words, thematerial does not affect the properties of the thioether or thecomposition in which the thioether is used. As used herein, the term“completely free” means that the material being discussed is not presentat all. In certain embodiments, the thioether of the present inventionis produced by reacting the foregoing reactants in the presence of aphase transfer catalyst.

Suitable alpha, omega dihalo organic compounds have the chemical formulaX—R—Y, where X and Y are halogens and R is an organic group. X and Y maybe different halogen atoms or the same halogen atoms. By “alpha, omega”is meant that the halogen atoms are believed to be attached to oppositeends of the organic group. Suitable halogens include, for example,chlorine, bromine, and iodine. Suitable organic groups include, forexample, alkyl groups with 3 or more carbon atoms, aryl groups,alkylaryl groups, alkoxy groups, and arylalkoxy groups. In certainembodiments, the organic group comprises an alkoxy group, specificexamples of which can be illustrated by the chemical formulas (V) and(VI):

CH₂—CH₂—OCH₂—OCH₂—CH₂—  (V)

CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—  (VI).

In some embodiments, the organic group may comprise a sulfur atom,specific examples of which can be illustrated by the chemical formulas(VII) and (VIII):

—CH₂H₂—S—CH₂H₂—  (VII)

CH₂—CH₂—S—CH₂—CH(CH₃)—  (VIII).

One specific example of an alpha, omega dihalo organic compound that issuitable for use in the present invention is bis(2-chloroethyl) formal.

Suitable metal hydrosulfides have the formula M-SH, where M is a metal.Specific examples of suitable metal hydrosulfides include, for example,sodium hydrosulfide, potassium hydrosulfide, lithium hydrosulfide,rubidium hydrosulfide, cesium hydrosulfide, as well as mixtures of twoor more of the foregoing. These metal hydrosulfides can be used, forexample, as hydrates, aqueous mixtures or anhydrous.

Suitable metal hydroxides have the formula M-(OH)_(x), where M is ametal and x is 1, 2, or 3. Specific examples of suitable metalhydroxides include, for example, lithium hydroxide, sodium hydroxide,potassium hydroxide, calcium hydroxide, barium hydroxide, as well asmixtures of two or more of the foregoing. These metal hydroxides can beused, for example, as hydrates, aqueous mixtures or anhydrous.

Suitable phase transfer catalysts (PTCs) include, for example,quaternary ammonium salts, phosphonium salts, and crown ethers. A moredetailed description of phase transfer catalysis and descriptions ofcompounds suitable as PTCs can be found in E. V. Dehmlow, “Catalysis,Phase Transfer,” in volume 5 of the Kirk-Othmer Encyclopedia of ChemicalTechnology, 4th edition, Wiley (1996). Further examples of PTC's can befound in JP04046931, to T. Tozawa et. al. In certain embodiments of thepresent invention, the phase transfer catalyst comprisestetrabutylammonium bromide, 18-crown-6, tetraphenylphosphonium halide,and/or methyltributylammonium chloride. In certain embodiments, asuitable amount of PTC is 0.01 to 10 mole % based on the moles of thealpha, omega dihalo organic compound or compounds, such as 0.05 to 2.0mole %.

As indicated, a polyfunctionalizing agent may also be used to preparecertain thioethers of the present invention, if desired. In theseembodiments, suitable polyfunctionalizing agents include, for example,trihalo organic compounds, such as trihalo alkyl compounds, for example,trihalo propane. Suitable halogens again include, for example, chlorine,bromine, and iodine. In certain embodiments, the polyfunctionalizingagent comprises 1,2,3-trichloropropane, 1,1,1-tris(chloromethyl)propane,1,1,1-tris(chloromethyl)ethane, and/or 1,3,5-tris(chloromethyl)benzene.In certain embodiments, a suitable amount of trihalo organic compound(s)is 0 to 10 moles of trihalo organic compound per 100 moles of alpha,omega dihalo organic compound(s), such as 1 to 5 moles of trihaloorganic compound(s) per 100 moles of alpha, omega dihalo organiccompound(s), or, in some cases 3 moles of trihalo organic compound(s)per 100 moles of alpha, omega dihalo organic compounds. The trihaloorganic compound(s), if used, is often mixed with the alpha, omegadihalo organic compound(s) so that the mixed halo compounds are addedtogether to the reaction mixture.

In certain embodiments, the thioether described above is a liquid atroom temperature. Moreover, in certain embodiments, the previouslydescribed thioether has a viscosity, at 100% solids, of no more than1500 poise, such as 40-500 poise, at a temperature of about 25° C. and apressure of about 760 mm Hg determined according to ASTM D-2849 §79-90using a Brookfield CAP 2000 viscometer. Any endpoint within theforegoing ranges can also be used.

As indicated, in certain embodiments, the thioether described above hasa number average molecular weight of 300 to 10,000 grams per mole, suchas 1,000 to 8,000 grams per mole, the molecular weight being determinedby gel-permeation chromatography using a polystyrene standard. Anyendpoints within the foregoing ranges can also be used.

In certain embodiments, the T_(g) of the thioether of the presentinvention is not higher than −55° C., such as not higher than −60° C.

The Examples herein further illustrate suitable methods for makingembodiments of the thioethers of the present invention.

As indicated, certain embodiments of the present invention are directedto compositions, such as sealant, coating, and/or electrical pottingcompositions that include the previously described thioethers. As usedherein, the term “sealant composition” refers to a composition that iscapable of producing a film that has the ability to resist atmosphericconditions, such as moisture and temperature and at least partiallyblock the transmission of materials, such as water, fuel, and otherliquid and gasses. In certain embodiments, the sealant compositions ofthe present invention are useful, e.g., as aerospace sealants andlinings for fuel tanks. In certain embodiments, the compositioncomprises a thioether as described above; a curing agent; and a filler.

In certain embodiments, the compositions of the present inventioncomprise, in addition to a thioether as described earlier, one or moreadditional sulfur-containing polymers. As used herein, the term“sulfur-containing polymer” refers to any polymer having at least onesulfur atom, including, but not limited to, polymeric thiols,polythiols, thioethers, polythioethers and polysulfides. A “thiol”, asused herein, refers to a compound comprising a thiol or mercaptan group,that is, an “SH” group, either as the sole functional group or incombination with other functional groups, such as hydroxyl groups, as isthe case with, for example, thioglycerols. A “polythiol” refers to sucha compound having more than one SH group, such as a dithiol or higherfunctionality thiol. Such groups are typically terminal and/or pendentsuch that they have an active hydrogen that is reactive with otherfunctional groups. As used herein, the term “polysulfide” refers to anycompound that comprises a sulfur-sulfur linkage (—S—S—). A “polythiol”can comprise both a terminal and/or pendant sulfur (—SH) and anon-reactive sulfur atom (—S— or (—S—S—)). Thus, the term “polythiol”generally encompasses “polythioether” and “polysulfide” as well.Suitable sulfur-containing polymers include, for example, thosedisclosed in U.S. Pat. Nos. 6,172,179, 6,509,418 and 7,009,032,incorporated by reference herein. Any sulfur-containing polymer usedaccording to the present invention can further comprise additionalfunctionality, including but not limited to hydroxyl functionality andepoxy functionality.

In certain embodiments, the thioether of the present invention ispresent in the composition of the present invention in an amount of atleast 30 weight percent, such as least 40 weight percent, or, in somecases, at least 45 weight percent, based on the total weight ofnon-volatile components in the composition. In certain embodiments, thethioether of the present invention is present in the composition of thepresent invention in an amount of no more than 90 weight percent, suchas no more than 80 weight percent, or, in some cases, no more than 75weight percent, based on the weight of all non-volatile components ofthe composition.

As indicated, certain embodiments of the curable compositions of thepresent invention also comprise a curing agent. Curing agents useful incertain compositions of the invention include epoxy resins, for example,hydantoin diepoxide, diglycidyl ether of bisphenol-A, diglycidyl etherof bisphenol-F, Novolak type epoxides, and any of the epoxidizedunsaturated and phenolic resins. Other useful curing agents includeunsaturated compounds, such as acrylic and methacrylic esters ofcommercially available polyols, unsaturated synthetic or naturallyoccurring resin compounds, triallylcyanurate, and olefinic terminatedderivatives of the compounds of the present invention.

Isocyanate functional compounds can also be useful curing agents in thecompositions of the present invention. Suitable isocyanate functionalcompounds include, but are not limited to, polymeric polyisocyanates,non-limiting examples of which include polyisocyanates having backbonelinkages chosen from urethane linkages (—NH(O)—O—), thiourethanelinkages (—NH—C(O)—S—), thiocarbamate linkages (—NH—C(S)—O—),dithiourethane linkages (—NH—C(S)—S—) and combinations thereof.

The molecular weight of such a polymeric polyisocyanate can vary. Incertain embodiments, the number average molecular weight (Mn) of eachcan be at least 100 grams/mole, or at least 150 grams/mole, or less than15,000 grams/mole, or less than 5000 grams/mole. The number averagemolecular weight values recited herein can be determined by gelpermeation chromatography (GPC) using polystyrene standards.

Non-limiting examples of suitable polyisocyanates, also includenon-polymeric aliphatic polyisocyanates, cycloaliphatic polyisocyanateswherein one or more of the isocyanato groups are attached directly tothe cycloaliphatic ring, cycloaliphatic polyisocyanates wherein one ormore of the isocyanato groups are not attached directly to thecycloaliphatic ring, aromatic polyisocyanates wherein one or more of theisocyanato groups are attached directly to the aromatic ring, andaromatic polyisocyanates wherein one or more of the isocyanato groupsare not attached directly to the aromatic ring.

In certain embodiments, the polyisocyanate includes, but is not limitedto, aliphatic or cycloaliphatic diisocyanates, aromatic diisocyanates,cyclic dimers and cyclic trimers thereof, and mixtures thereof.Non-limiting examples of suitable polyisocyanates include, but are notlimited to, Desmodur N 3300 (hexamethylene diisocyanate trimer) andDesmodur N 3400 (60% hexamethylene diisocyanate dimer and 40%hexamethylene diisocyanate trimer), which are commercially availablefrom Bayer.

In certain embodiments, the polyisocyanate includes dicyclohexylmethanediisocyanate and/or isomeric mixtures thereof. As used herein, the term“isomeric mixtures” refers to a mixture of the cis-cis, trans-trans, andcis-trans isomers of the polyisocyanate. Non-limiting examples ofisomeric mixtures for use in the present invention include thetrans-trans isomer of 4,4′-methylenebis(cyclohexyl isocyanate),hereinafter referred to as “PICM” (paraisocyanato cyclohexylmethane),the cis-trans isomer of PICM, the cis-cis isomer of PICM, and mixturesthereof.

Three suitable isomers of 4,4′-methylenebis(cyclohexyl isocyanate) foruse in the present invention are shown below.

In certain embodiments, the isomeric mixture can contain from 10-100percent of the trans,trans isomer of 4,4′-methylenebis(cyclohexylisocyanate) (PICM).

Additional diisocyanates that can be used in certain embodiments of thepresent invention include 3-isocyanato-methyl-3,5,5-trimethylcyclohexyl-isocyanate (“IPDI”) and meta-tetramethylxylylene diisocyanate(1,3-bis(1-isocyanato-1-methylethyl)-benzene) which is commerciallyavailable from Cytec Industries Inc. under the tradename TMXDI® (Meta)Aliphatic Isocyanate.

As used herein, the terms aliphatic and cycloaliphatic diisocyanatesrefer to 6 to 100 carbon atoms linked in a straight chain or cyclizedhaving two diisocyanate reactive end groups. In certain embodiments, thealiphatic and cycloaliphatic diisocyanates used in the present inventioncan include TMXDI and compounds of the formula R—(NCO)₂ wherein Rrepresents an aliphatic group or a cycloaliphatic group.

Additional non-limiting examples of suitable polyisocyanates include,but are not limited to, ethylenically unsaturated polyisocyanates;alicyclic polyisocyanates; aromatic polyisocyanates wherein theisocyanate groups are not bonded directly to the aromatic ring, e.g.,α,α′-xylylene diisocyanate; aromatic polyisocyanates wherein theisocyanate groups are bonded directly to the aromatic ring, e.g.,benzene diisocyanate or methylene dibenzene diisocyanate, which has thestructure

polyisocyanates containing sulfide and/or disulfide linkages; aromaticpolyisocyanates containing sulfone linkages; sulfonic ester-typepolyisocyanates, e.g.,4-methyl-3-isocyanatobenzenesulfonyl-4′-isocyanato-phenol ester;aromatic sulfonic amide-type polyisocyanates; sulfur-containingheterocyclic polyisocyanates, e.g., thiophene-2,5-diisocyanate;halogenated, alkylated, alkoxylated, nitrated, carbodiimide modified,urea modified and biuret modified derivatives of polyisocyanatesthereof; and dimerized and trimerized products of polyisocyanatesthereof.

In certain embodiments, a diisocyanate of the following structure can beused:

wherein R₁₀ and R₁₁ are each independently C₁ to C₃ alkyl.

Examples of suitable ethylenically unsaturated polyisocyanates include,but are not limited to, butene diisocyanate and1,3-butadiene-1,4-diisocyanate.

Examples of suitable alicyclic polyisocyanates include, but are notlimited to, isophorone diisocyanate, cyclohexane diisocyanate,methylcyclohexane diisocyanate, bis(isocyanatomethyl)cyclohexane,bis(isocyanatocyclohexyl)methane, bis(isocyanatocyclohexyl)-2,2-propane,bis(isocyanatocyclohexyl)-1,2-ethane,2-isocyanatomethyl-3-(3-isocyanatopropyl)-5-isocyanatomethyl-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-3-(3-isocyanatopropyl)-6-isocyanatomethyl-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-2-(3-isocyanatopropyl)-5-isocyanatomethyl-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-2-(3-isocyanatopropyl)-6-isocyanatomethyl-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-3-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo[2.2.1]-heptane,2-isocyanatomethyl-2-(3-isocyanatopropyl)-5-(2-isocyanatoethyl)-bicyclo[2.2.1]-heptaneand2-isocyanatomethyl-2-(3-isocyanatopropyl)-6-(2-isocyanatoethyl)-bicyclo[2.2.1]-heptane.

Examples of suitable aromatic polyisocyanates wherein the isocyanategroups are not bonded directly to the aromatic ring also include, butare not limited to, bis(isocyanatoethyl)benzene,α,α,α′,α′-tetramethylxylylene diisocyanate,1,3-bis(1-isocyanato-1-methylethyl)benzene, bis(isocyanatobutyl)benzene,bis(isocyanatomethyl)naphthalene, bis(isocyanatomethyl)diphenyl ether,bis(isocyanatoethyl)phthalate, mesitylene triisocyanate and2,5-di(isocyanato ethyl)furan, and meta-xylylene diisocyanate.

Examples of suitable aromatic polyisocyanates having isocyanate groupsbonded directly to the aromatic ring also include, but are not limitedto, phenylene diisocyanate, ethylphenylene diisocyanate,isopropylphenylene diisocyanate, dimethylphenylene diisocyanate,diethylphenylene diisocyanate, diisopropylphenylene diisocyanate,trimethylbenzene triisocyanate, benzene triisocyanate, naphthalenediisocyanate, methylnaphthalene diisocyanate, biphenyl diisocyanate,ortho-toluidine diisocyanate, ortho-tolylidine diisocyanate,ortho-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate,bis(3-methyl-4-isocyanatophenyl)methane, bis(isocyanatophenyl)ethylene,3,3′-dimethoxy-biphenyl-4,4′-diisocyanate, triphenylmethanetriisocyanate, polymeric 4,4′-diphenylmethane diisocyanate, naphthalenetriisocyanate, diphenylmethane-2,4,4′-triisocyanate,4-methyldiphenylmethane-3,5,2′,4′,6′-pentaisocyanate, diphenyletherdiisocyanate, bis(isocyanatophenylether)ethyleneglycol,bis(isocyanatophenylether)-1,3-propyleneglycol, benzophenonediisocyanate, carbazole diisocyanate, ethylcarbazole diisocyanate anddichlorocarbazole diisocyanate.

Examples of suitable aromatic polyisocyanates containing sulfide ordisulfide linkages include, but are not limited to,diphenylsulfide-2,4′-diisocyanate, diphenylsulfide-4,4′-diisocyanate,3,3′-dimethoxy-4,4′-diisocyanatodibenzyl thioether,bis(4-isocyanatomethylbenzene)-sulfide,diphenyldisulfide-4,4′-diisocyanate,2,2′-dimethyldiphenyldisulfide-5,5′-diisocyanate,3,3′-dimethyldiphenyldisulfide-5,5′-diisocyanate,3,3′-dimethyldiphenyldisulfide-6,6′-diisocyanate,4,4′-dimethyldiphenyldisulfide-5,5′-diisocyanate,3,3′-dimethoxydiphenyldisulfide-4,4′-diisocyanate and4,4′-dimethoxydiphenyldisulfide-3,3′-diisocyanate.

Examples of suitable aromatic polyisocyanates containing sulfonelinkages also include, but are not limited to,diphenylsulfone-4,4′-diisocyanate, diphenylsulfone-3,3′-diisocyanate,benzidinesulfone-4,4′-diisocyanate,diphenylmethanesulfone-4,4′-diisocyanate,4-methyldiphenylmethanesulfone-2,4′-diisocyanate,4,4′-dimethoxydiphenylsulfone-3,3′-diisocyanate,3,3′-dimethoxy-4,4′-diisocyanatodibenzylsulfone,4,4′-dimethyldiphenylsulfone-3,3′-diisocyanate,4,4′-di-tert-butyl-diphenylsulfone-3,3′-diisocyanate and4,4′-dichlorodiphenylsulfone-3,3′-diisocyanate.

Examples of suitable polyisocyanates include, but are not limited to,aromatic sulfonic amide-type polyisocyanates, such as4-methyl-3-isocyanato-benzene-sulfonylanilide-3′-methyl-4′-isocyanate,dibenzenesulfonyl-ethylenediamine-4,4′-diisocyanate,4,4′-methoxybenzenesulfonyl-ethylenediamine-3,3′-diisocyanate and4-methyl-3-isocyanato-benzene-sulfonylanilide-4-ethyl-3′-isocyanate.

In addition, useful cures can be obtained through oxidative coupling ofthe thiol groups using organic and inorganic peroxides (e.g., MnO₂)known to those skilled in the art. Selection of the particular curingagent may affect the T_(g) of the cured composition. For example, curingagents that have a T_(g) significantly lower than the T_(g) of thethioether(s) may lower the T_(g) of the cured composition.

Depending on the nature of the thioether(s) used in the composition, thecomposition will often contain 90% to 150% of the stoichiometric amount,such as 95 to 125%, of the selected curing agent(s).

Fillers useful in the certain embodiments of the compositions of thepresent invention include those commonly used in the art, includingconventional inorganic fillers, such as carbon black and calciumcarbonate (CaCO₃), as well as lightweight fillers. Suitable lightweightfillers include, for example, those described in U.S. Pat. No. 6,525,168at col. 4, lines 23-55, the cited portion of which being incorporatedherein by reference. In certain embodiments, the compositions include 5to 60 weight percent of the filler or combination of fillers, such as 10to 50 weight percent, based on the total weight of the composition.

As will be appreciated, the thioethers, curing agents and fillersemployed in certain compositions of the invention, as well as optionaladditives as described below, should be selected so as to be compatiblewith each other. Selection of compatible ingredients for the inventivecompositions can readily be performed by those skilled in the artwithout recourse to undue experimentation.

In certain embodiments, the compositions of the present invention arecurable at a minimum temperature of 0° C. (i.e., at a temperature of 0°C. or higher), such as −10° C., or, in some cases, −20° C., and have aT_(g) when cured not higher than −55° C., such as not higher than −60°C., or, in some cases, not higher than −65° C.

In addition to the foregoing ingredients, certain compositions of theinvention can optionally include one or more of the following:colorants; thixotropes; accelerators; retardants; adhesion promoters;solvents; and masking agents, among other components.

As used herein, the term “colorant” means any substance that impartscolor and/or other opacity and/or other visual effect to thecomposition. The colorant can be added to the coating in any suitableform, such as discrete particles, dispersions, solutions and/or flakes.A single colorant or a mixture of two or more colorants can be used inthe coatings of the present invention.

Example colorants include pigments, dyes and tints, such as those usedin the paint industry and/or listed in the Dry Color ManufacturersAssociation (DCMA), as well as special effect compositions. A colorantmay include, for example, a finely divided solid powder that isinsoluble but wettable under the conditions of use. A colorant can beorganic or inorganic and can be agglomerated or non-agglomerated.Colorants can be incorporated into the coatings by use of a grindvehicle, such as an acrylic grind vehicle, the use of which will befamiliar to one skilled in the art.

Example pigments and/or pigment compositions include, but are notlimited to, carbazole dioxazine crude pigment, azo, monoazo, disazo,naphthol AS, salt type (lakes), benzimidazolone, condensation, metalcomplex, isoindolinone, isoindoline and polycyclic phthalocyanine,quinacridone, perylene, perinone, diketopyrrolo pyrrole, thioindigo,anthraquinone, indanthrone, anthrapyrimidine, flavanthrone, pyranthrone,anthanthrone, dioxazine, triarylcarbonium, quinophthalone pigments,diketo pyrrolo pyrrole red (“DPPBO red”), titanium dioxide, carbon blackand mixtures thereof. The terms “pigment” and “colored filler” can beused interchangeably.

Example dyes include, but are not limited to, those that are solventand/or aqueous based such as pthalo green or blue, iron oxide, bismuthvanadate, anthraquinone, perylene, aluminum and quinacridone.

Example tints include, but are not limited to, pigments dispersed inwater-based or water miscible carriers such as AQUA-CHEM 896commercially available from Degussa, Inc., CHARISMA COLORANTS andMAXITONER INDUSTRIAL COLORANTS commercially available from AccurateDispersions division of Eastman Chemical, Inc.

As noted above, the colorant can be in the form of a dispersionincluding, but not limited to, a nanoparticle dispersion. Nanoparticledispersions can include one or more highly dispersed nanoparticlecolorants and/or colorant particles that produce a desired visible colorand/or opacity and/or visual effect. Nanoparticle dispersions caninclude colorants such as pigments or dyes having a particle size ofless than 150 nm, such as less than 70 nm, or less than 30 nm.Nanoparticles can be produced by milling stock organic or inorganicpigments with grinding media having a particle size of less than 0.5 mm.Example nanoparticle dispersions and methods for making them areidentified in U.S. Pat. No. 6,875,800 B2, which is incorporated hereinby reference. Nanoparticle dispersions can also be produced bycrystallization, precipitation, gas phase condensation, and chemicalattrition (i.e., partial dissolution). In order to minimizere-agglomeration of nanoparticles within the coating, a dispersion ofresin-coated nanoparticles can be used. As used herein, a “dispersion ofresin-coated nanoparticles” refers to a continuous phase in which isdispersed discreet “composite microparticles” that comprise ananoparticle and a resin coating on the nanoparticle. Exampledispersions of resin-coated nanoparticles and methods for making themare identified in United States Patent Application Publication2005-0287348 A1, filed Jun. 24, 2004, U.S. Provisional Application No.60/482,167 filed Jun. 24, 2003, and United States patent applicationSer. No. 11/337,062, filed Jan. 20, 2006, which is also incorporatedherein by reference.

Example special effect compositions that may be used in the compositionsof the present invention include pigments and/or compositions thatproduce one or more appearance effects such as reflectance,pearlescence, metallic sheen, phosphorescence, fluorescence,photochromism, photosensitivity, thermochromism, goniochromism and/orcolor-change. Additional special effect compositions can provide otherperceptible properties, such as opacity or texture. In a non-limitingembodiment, special effect compositions can produce a color shift, suchthat the color of the coating changes when the coating is viewed atdifferent angles. Example color effect compositions are identified inU.S. Pat. No. 6,894,086, incorporated herein by reference. Additionalcolor effect compositions can include transparent coated mica and/orsynthetic mica, coated silica, coated alumina, a transparent liquidcrystal pigment, a liquid crystal coating, and/or any compositionwherein interference results from a refractive index differential withinthe material and not because of the refractive index differentialbetween the surface of the material and the air.

In general, the colorant can be present in any amount sufficient toimpart the desired visual and/or color effect. The colorant may comprisefrom 1 to 65 weight percent of the present compositions, such as from 3to 40 weight percent or 5 to 35 weight percent, with weight percentbased on the total weight of the compositions.

Thixotropes, for example silica, are often used in an amount from 0.1 to5 weight percent, based on the total weight of the composition.

Cure catalysts known to the art, such as amines, often are present in anamount from 0.1 to 5 weight percent, based on the total weight of thecomposition. Specific examples of useful accelerators are, withoutlimitation, 1,4-diaza-bicyclo[2.2.2]octane (DABCO®, commerciallyavailable from Air Products, Chemical Additives Division, Allentown,Pa.) and DMP-300 (an accelerant composition including2,4,6-tris(dimethylaminomethyl)phenol, commercially available from Rohmand Haas. Philadelphia, Pa.). It has been surprisingly discovered,however, that certain embodiments of the present invention will cure atambient conditions even in the absence of any such cure accelerator.

Retardants, such as stearic acid, likewise often are used in an amountfrom 0.1 to 5 weight percent, based on the total weight of thecomposition. Adhesion promoters, if employed, are often present inamount from 0.1 to 15 weight percent, based on the total weight of thecomposition. Suitable adhesion promoters include phenolics, such asMETHYLON phenolic resin available from Occidental Chemicals, andorganosilanes, such as epoxy, mercapto or amino functional silanes, suchas A-187 and A-1100 available from OSi Specialties. Masking agents, suchas pine fragrance or other scents, which are useful in covering any lowlevel odor of the composition, are often present in an amount from 0.1to 1 weight percent, based on the total weight of the composition.

In certain embodiments, the compositions of the present inventioncomprise a plasticizer which, in at least some cases, may allow thecomposition to include thioether(s) which have a higher T_(g) than wouldordinarily be useful in an aerospace sealant. That is, use of aplasticizer may effectively reduce the T_(g) of the composition, andthus increase the low-temperature flexibility of the cured polymerizablecomposition beyond that which would be expected on the basis of theT_(g) of the thioethers alone. Plasticizers that are useful in certainembodiments of the compositions of the present invention include, forexample, phthalate esters, chlorinated paraffins, and hydrogenatedterphenyls. The plasticizer or combination of plasticizers oftenconstitute 1 to 40 weight percent, such as 1 to 10 weight percent of thecomposition. In certain embodiments, depending on the nature and amountof the plasticizer(s) used in the composition, thioethers of theinvention which have T_(g) values up to −50° C., such as up to −55° C.,can be used.

In certain embodiments, the compositions of the present invention canfurther comprise one or more organic solvents, such as isopropylalcohol, in an amount ranging from, for example, 0 to 15 percent byweight on a basis of total weight of the composition, such as less than15 weight percent and, in some cases, less than 10 weight percent.

In certain embodiments, however, the compositions of the presentinvention are substantially free or, in some cases, completely free, ofany solvent, such as an organic solvent or an aqueous solvent, i.e.,water. Stated differently, in certain embodiments, the compositions ofthe present invention are substantially 100% active.

In certain embodiments, the compositions, such as the previouslydescribed sealant compositions, are embodied as multi-pack compositions,such as two-pack compositions, wherein one package comprises thepreviously described thioether polymer and the second pack comprises thecuring agent. The previously described additives and other materials canbe added to either package as desired or necessary. The two packages aresimply mixed together at or near the time of use.

The compositions of the present invention can be applied to any of avariety of substrates. Common substrates to which the compositions ofthe present invention are applied can include titanium, stainless steel,aluminum, anodized, primed, organic coated and chromate coated formsthereof, epoxy, urethane, graphite, fiberglass composite, KEVLAR®,acrylics and polycarbonates.

The compositions of the present invention can be applied directly ontothe surface of a substrate or over an underlayer by any suitable coatingprocess known to those of ordinary skill in the art, for example, byextruding, dip coating, direct roll coating, reverse roll coating,curtain coating, spray coating, brush coating, vacuum coating andcombinations thereof. The method and apparatus for applying thecomposition to the substrate may be determined, at least in part, by theconfiguration and type of substrate material.

In certain embodiments, the compositions of the present invention arefuel-resistant. As used herein, the term “fuel resistant” means that thecompositions of the present invention, when applied to a substrate andcured, can provide a cured product, such as a sealant, that has apercent volume swell of not greater than 40%, in some cases not greaterthan 25%, in some cases not greater than 20%, in yet other cases notmore than 10%, after immersion for one week at 140° F. (60° C.) andambient pressure in jet reference fluid (JRF) type 1 according tomethods similar to those described in ASTM D792 or AMS 3269,incorporated herein by reference. Jet reference fluid JRF type 1, asemployed herein for determination of fuel resistance, has the followingcomposition (see AMS 2629, issued Jul. 1, 1989), §3.1.1 et seq.,available from SAE (Society of Automotive Engineers, Warrendale, Pa.)(that is incorporated herein by reference): herein by reference):

Toluene 28 ± 1% by volume Cyclohexane (technical) 34 ± 1% by volumeIsooctane 38 ± 1% by volume Tertiary dibutyl disulfide 1 ± 0.005% byvolume (doctor sweet)

Indeed, it was a surprising discovery that certain embodiments of thepresent invention exhibit excellent fuel-resistance properties (percentvolume swell of not greater than 10% as described above, which is oftenassociated with polysulfides) as well as excellent elevated-temperatureresistance (good tensile strength and elongation properties after 8hours exposure at 360° F., which is often associated withpolythioethers).

In certain embodiments, cured products, such as sealants, of the presentinvention have good low temperature flexibility as determined by knownmethods, for example, by the methods described in AMS (AerospaceMaterial Specification) 3267 §4.5.4.7, MIL-S (MilitarySpecification)-8802E §3.3.12 and MIL-S-29574, and by methods similar tothose described in ASTM (American Society for Testing and Materials)D522-88, which are incorporated herein by reference. Cured formulationshaving good low temperature flexibility are desirable in aerospaceapplications because the formulations are subjected to wide variationsin environmental conditions, such as temperature and pressure, andphysical conditions such as joint contraction and expansion andvibration.

In certain embodiments, compositions of the present invention also curerelatively quickly under ambient conditions. For example, in certainembodiments, the compositions provide a tack free film in no more than 1hour, in some cases no more than ½ hour, after application and cure inambient conditions. For purposes of the present invention tack free timeis measured in accordance with the procedure described in AMS 3265B, §3.6.8, test procedure AS5127/1, § 5.8.

In certain embodiments, sealant compositions of the present inventionprovide a cured product, such as a sealant, having an elongation of atleast 100% and a tensile strength of at least 500 psi when measured inaccordance with the procedure described in AMS 3279, § 3.3.17.1, testprocedure AS5127/1, § 7.7.

In certain embodiments, sealant compositions of the present inventionprovide a cured product, such as a sealant having a lap shear strengthof greater than 200 psi, in some cases at least 400 psi when measuredaccording to the procedure described in BSS 7272.

As should be apparent from the foregoing description, the presentinvention is also directed to methods for sealing an aperture utilizinga composition of the present invention. These methods comprise (a)applying a composition of the present invention to a surface to seal theaperture; and (b) allowing the composition to cure under, for example,ambient conditions. As will also be appreciated, the present inventionis also directed to aerospace vehicles comprising at least one surfacecoated with a coating composition of the present invention as well asaerospace vehicles comprising at least one aperture that is sealed witha sealant composition of the present invention.

Illustrating the invention are the following examples, which, however,are not to be considered as limiting the invention to their details.Unless otherwise indicated, all parts and percentages in the followingexamples, as well as throughout the specification, are by weight.

EXAMPLES Example 1 Synthesis of Mercaptan-Capped Polythioether

Solid flakes of sodium hydrosulfide hydrate (834.04 g; purity: 70%;10.42 moles) were charged into a 5 liter 4-neck flask followed by water(1.696 Kg). Flask was flushed with nitrogen and stirring was started.Freshly-prepared aqueous sodium hydroxide (306.18 g, concentration: 50%;3.83 moles) was added into the solution of sodium hydrosulfide followedby phase transfer catalyst A-175 (14.06 g, 0.06 mole). Reaction mixturewas heated to 160° F. A mixture of 2-chloroethylformal (748.89 g, 4.33moles) and 1,2,3-trichloropropane (19.86 g, 0.13 mole) was added at160-165° F. over 6.5 hr and stirring was continued for another 2 hr.Heating was continued at 175-180° F. for 8 hr and at 185-190° F. for 8hr. Reaction mixture was cooled to ambient temperature.Partially-emulsified polymeric layer was separated and washed with five400 ml portions of water. The last washing was free of sodiumhydrosulfide as indicated by lead acetate paper test. Polymeric layerwas then washed with acidified water (400 ml water containing 2 ml of95% formic acid; ph: 2-3) and dissolved in 1.2 liter of chloroform.Organic portion was separated, filtered through a band of anhydroussodium sulfate and concentrated to give 583g of a off-white polymer;mercaptan equivalent weight: 1816 (iodine titration method); viscosity:122P (spindle no. 6, @100 RPM; Brookfield Cap 2000 viscometer).

Example 2 Preparation of Sealant Formulation

Part A of the sealant formulation was prepared by mixing 59.9 parts byweight of the polythioether of Example 1, 39.0 parts by weight calciumcarbonate, 0.6 parts by weight of titanium dioxide, and 0.5 parts byweight of 1,4-diaza-bicyclo[2.2.2]octane (DABCO®, commercially availablefrom Air Products, Chemical Additives Division, Allentown, Pa.).

Part B of the sealant formulation was prepared by mixing 0.9 parts byweight of an epoxysilane adhesion promoter, 11.1 parts by weight HB-40modified polyphenyl (commercially available from Solutia, Inc.); 41.6parts by weight calcium carbonate; 46.2 parts by weight Epon 828 epoxyresin; and 0.2 parts by weight carbon black.

The sealant was made for testing by mixing 100 parts of Part A and 14parts of Part B. A sealant prepared from the above composition exhibitedthe properties set forth in Table 1.

TABLE 1 Tested according to methods in SAE AS5127/1 (except as noted)Property Result Application Time 2 hours Tack Free Time 4 hours 24 hourshardness 48 Shore A 14 days Hardness 52 Shore A Volume swell-JRF Type 16% 7 days @140° F. Weight Loss-JRF Type 1 5% 7 days @140° F. Tensile &Elongation Standard Cure 7 days 300 psi/400% 7 days at 140° F. in JRFtype I 250 psi/400% 8 hours @ 360° F. 180 psi/130% Adhesion Tested onMil C-27725 panel Standard Cure 7 days 43 pli 100% cohesive failure 7days at 140° F. in JRF type I 35 pli 100% cohesive failure

Whereas particular embodiments of this invention have been describedabove for purposes of illustration, it will be evident to those skilledin the art that numerous variations of the details of the presentinvention may be made without departing from the invention as defined inthe appended claims.

1-11. (canceled)
 12. A compound comprising a structure:—[—S—(RX)_(p)—(R₁X)_(q)—R₂—]_(n)— wherein: (a) R denotes a C₂₋₁₀n-alkylene group; a C₃₋₁₀ branched alkylene group; a C₆₋₈ cycloalkylenegroup; a C₆₋₁₄ alkylcycloalkylene; or a C₈₋₁₀ alkylarylene group; (b) R₁denotes a C₄; (c) R₂ denotes a C₂₋₁₀ n-alkylene group; a C₃₋₁₀ branchedalkylene group; a C₆₋₈ cycloalkylene group; a C₆₋₁₄ alkylcycloalkylene;or a C₈₋₁₀ alkylarylene group; (d) X denotes O or S; (e) p has a valueof 1 to 5; (f) q has a value of 1; and (g) n has a value of at least 1.13. The compound of claim 12, wherein n has a value of at least
 2. 14.The compound of claim 13, wherein n has a value of no more than
 60. 15.The compound of claim 14, wherein n has a value of 25 to
 35. 16-19.(canceled)
 20. A compound that is the reaction product of reactantscomprising: (a) an alpha, omega dihalo organic compound, (b) a metalhydrosulfide, and (c) a metal hydroxide.
 21. The compound of claim 20,wherein the reactants further comprise: (d) a polyfunctionalizing agent.22. The compound of claim 20, wherein the reactants are substantiallyfree of a polythiol.
 23. The compound of claim 20, wherein the alpha,omega dihalo organic compound has the chemical formula X—R—Y, where Xand Y are halogens and R is an organic group comprising an alkoxy group.24. The compound of claim 23, wherein the alkoxy group comprises:—CH₂—CH₂—O—CH₂—O—CH₂—CH₂—, and/or—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—. 25-26. (canceled)
 27. A compositioncomprising the compound of claim
 20. 28. The composition of claim 27,wherein the composition is a sealant composition further comprising acuring agent and a filler. 29-30. (canceled)
 31. A method for making asulfur-containing compound, comprising reacting reactants comprising:(a) an alpha, omega dihalo organic compound, (b) a metal hydrosulfide,and (c) a metal hydroxide, in the presence of a phase transfer catalyst.32. The method of claim 31, wherein the reactants further comprise: (d)a polyfunctionalizing agent.
 33. The method of claim 31, wherein thereactants are substantially free of a polythiol.
 34. The method of claim31, wherein the alpha, omega dihalo organic compound has the chemicalformula X—R—Y, where X and Y are halogens and R is an organic groupcomprising an alkoxy group.
 35. The method of claim 34, wherein thealkoxy group comprises:—CH₂—CH₂—O—CH₂—O—CH₂—CH₂—, and/or—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—.
 36. The composition of claim 28, furthercomprising an additional sulfur-containing polymer.
 37. The compositionof claim 36, wherein the additional sulfur-containing polymer comprisesa polysulfide or a polythioether.
 38. The compound of claim 21, whereinthe polyfunctionalizing agent comprises a trihalo alkyl compound. 39.The method of claim 32, wherein the polyfunctionalizing agent comprisesa trihalo alkyl compound.